cc https://github.com/paritytech/ci_cd/issues/1088

### Improved devx of running many pallets simultaneously

Changes to /cmd:
- Replace (flip) `--continue-on-fail` with `--fail-fast`, but only for
`bench`. This makes all pallets/runtimes run non-stop by default, as it
was primary use-case during tests
- The list of successful/failed pallets was hard to find within tons of
logs, so decided to write only needed logs in a file, and output as a
summary in the workflow and in the comment
- Side fix: updated `tasks_example` to `pallet_example_tasks` to make
compliant with standard naming

<img width="1006" alt="image"
src="https://github.com/user-attachments/assets/14896041-7018-4a0d-92b7-4508e81913c2">

+ added command results to workflow summary:
<img width="1275" alt="image"
src="https://github.com/user-attachments/assets/b4a8afdb-dc9f-4ff9-9720-28a88956035f">

---------

Co-authored-by: GitHub Action <action@github.com>

Related to
https://github.com/paritytech/polkadot-sdk/pull/5924#issuecomment-2393558697

improve prdoc arguments validation & help:
- convert audiences options to snake_case. Fixes
https://github.com/paritytech/polkadot-sdk/issues/5927
  - support more than one audiences
  - define allowed bump options
- infer --pr from the actual PR (now it's optional, can still be
overwritten)


![image](https://github.com/user-attachments/assets/24e18fe2-2f67-4ce0-90e4-34f6c2f860c9)

Test evidence:
https://github.com/paritytech-stg/polkadot-sdk/pull/52/commits/6dd274e3678d287c163cfa6cb696acee9852767d

cc https://github.com/paritytech/ci_cd/issues/1039

Fixes https://github.com/paritytech/polkadot-sdk/issues/5647

- [x]  create new command (reusing original py module)
- [x]  add unit-test cases (just the fact of proxy)
- [x]  update docs

Prdoc is now published as a Parity fork under the
[`parity-prdoc`](https://crates.io/crates/parity-prdoc) crate after the
directions diverged from the ideas of the original creator (discussions
[here](https://github.com/paritytech/prdoc/pull/40) and
[here](https://github.com/paritytech/prdoc/issues/36)).
Now updating the install instructions here.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

Closes https://github.com/paritytech/product-engineering/issues/93

- Deprecates old command bot bash scripts. New cmd implementation is
re-written on Python
- Deprecates `sync` command, which was never used
- Benchmarks:
- Uses new
[frame-omni-bencher](https://crates.io/crates/frame-omni-bencher)
- Simplifies usage to only providing a runtime and/or pallet name (even
multiple runtimes or pallets)
- Supports sub-modules (like `/cmd bench --runtime dev --pallet
pallet_asset_conversion_ops`)
- Can regenerate all weights with one command (substrate, polkadot,
cumulus) for provided pallet(s) name
- Adds [subweight](https://crates.io/crates/subweight-core) diff as a
result of bench command

A follow-up to https://github.com/paritytech/polkadot-sdk/pull/5447

Instead of having an option to select a PR template (like is the case
with issues), this change will make the one PR template we have the
default, it will show up for every new PR.

Also updated one link so it works properly in the PR body.

Hello
I found several spelling errors.
Br, Elias.

Uses custom metadata to exclude chain-specific crates.  
The only concern is that devs who want to use chain-specific crates,
still need to select matching versions numbers. Could possibly be
addresses with chain-specific umbrella crates, but currently it should
be possible to use [psvm](https://github.com/paritytech/psvm).

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

An attempt to improve [the
docs](https://paritytech.github.io/polkadot-sdk/master/polkadot_sdk_docs/index.html)
by applying various corrections:

- grammar/stylistics,
- formatting,
- broken links,
- broken markdown table,
- outdated vscode setting name,
- typos,
- consistency,
- etc.

Part of https://github.com/paritytech/eng-automation/issues/10

Co-authored-by: Bastian Köcher <git@kchr.de>

cc https://github.com/paritytech/ci_cd/issues/974

---------

Co-authored-by: command-bot <>
Co-authored-by: Bastian Köcher <info@kchr.de>

Updating the prdoc doc file to be a bit more useful for new contributors
and adding a SemVer section.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

cc https://github.com/paritytech/ci_cd/issues/943

A brief explanation of the Deprecation Checklist is added to the
Contributing notes with a link to it

This PR is a continuation of
https://github.com/paritytech/polkadot-sdk/pull/2102 and part of an
initiative started here https://hackmd.io/@romanp/rJ318ZCEp
What has been done:
- The content under `docs/*` (with the exception of `docs/mermaid`) has
been moved to `docs/contributor/`
- Developer Hub has been renamed to Polkadot SDK Docs, and the crate has
been renamed from `developer-hub` to `polkadot-sdk-docs`
- The content under `developer-hub/*` has been moved to `docs/sdk`

---
Original PR https://github.com/paritytech/polkadot-sdk/pull/2565, it has
been close due to too many rebase conflicts

---------

Co-authored-by: Serban Iorga <serban@parity.io>
Co-authored-by: Chevdor <chevdor@users.noreply.github.com>
Co-authored-by: Egor_P <egor@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>